直立工作面柔索驱动检测机器人的设计研究

为解决电厂锅炉内壁、船体、玻璃幕墙外墙面等大型构件直立面检测维护的工程难题,研制了一种新型的过约束柔索驱动检测机器人。研究了不同的柔索驱动定位机构及构型的差异,并根据工程应用需要,总结了柔索驱动检测机器人所需具备的基本功能,据此选择了功能更易实现的过约束定位机构,然后进行了系统的构型设计和运动机构结构的设计。通过一定的合理简化,建立了系统运动分析模型和运动机构受力模型,根据力矢量及几何闭合条件,得出了柔索运动方程和静力平衡方程,求解出了柔索的运动参数和受力解析解。试制了样机并搭载CCD相机进行了相关的验证试验,实现了柔索驱动检测机器人的基本功能。

Seismic design and analysis of nuclear power plant structures

The seismic design and analysis of nuclear power plant (NPP) begin with the seismic hazard assessment and design ground motion development for the site. The following steps are needed for the seismic hazard assessment and design ground motion development:a. the development of regional seismo-tectonic model with seismic source areas within 500 km radius centered to the site;b. the development of strong motion prediction equations; c. logic three development for taking into account uncertainties and seismic hazard quantification;d. the development of uniform hazard response spectra for ground motion at the site;e. simulation of acceleration time histories compatible with uniform hazard response spectra. The following phase two in seismic design of NPP structures is the analysis of structural response for the design ground motion. This second phase of the process consists of the following steps:a. development of structural models of the plant buildings;b. development of the soil model underneath the plant buildings for soilstructure interaction response analysis;c. determination of instructure response spectra for the plant buildings for the equipment response analysis. In the third phase of the seismic design and analysis the equipment is analyzed on the basis of in-structure response spectra. For this purpose the structural models of the mechanical components and piping in the plant are set up. In large 3D-structural models used today the heaviest equipment of the primary coolant circuit is included in the structural model of the reactor building. In the fourth phase the electrical equipment and automation and control equipment are seismically qualified with the aid of the in-structure spectra developed in the phase two using large three-axial shaking tables. For this purpose the smoothed envelope spectra for calculated in-structure spectra are constructed and acceleration time is fitted to these smoothed envelope spectra.

Structural Analysis and Design of Steel Connections Using Component-Based Finite Element Model

This paper introduces CBFEM （component-based finite element model） which is a new method to analyze and design connections of steel structures. Design focused CM （component model） is compared to FEM （finite elements models）. Procedure for composition of a model based on usual production process is used in CBFEM. Its results are compared to those obtained by component method for portal frame eaves moment connection with good agreement. Design of moment resistant column base is demonstrated by a case loaded by two directional bending moments and normal force. Interaction of several connections in one complex joint is explained in the last example. This paper aims to provide structural engineers with a new tool to effectively analyze and design various joints of steel structures.

3D building modeling： A critical investigation practice to learning, analyzing and deconstruting architecture

The research deal with the reconstruction through digital 3D CAAD （Computer Aided Architectural Design） modeling of masterpieces of modem and contemporary architecture. The charm of reconstruction through digital modeling is far less than that of work done on traditional maquette, indeed, makes much deeper level of detail and specificity from knowing. We had to know many technical characteristics of the buildings beyond size, like static-structural features, physical features, economic features and others. In this way＇ the model become real-simulation, a simulated architectural model in all aspects. In addition to these aspects we deeply analyze also the formal, morphological, historical and architectural aspects. The idea is to revitalize and re-discover the logics and the rules of the projected constructions that the designer architect have invented for each masterpiece of architecture, through the comprehension of how is done. The proportional analysis of the modularity on which the design is based is mandatory subject of investigation.

Research on failure scenarios of domes based on form vulnerability

In this paper, form vulnerability theory was applied to the analysis of the failure mechanisms of single-layer latticed spherical shells subjected to seismic excitations. Three 1/10 scale testing models were designed with characteristics as follows： Model 1 possesses overall uniform stiffness and is expected to collapse in the strength failure mode as some members become plastic; Model 2 possesses six man-made weak parts located on six radial main rib zones and is expected to collapse in the dynamic in- stability mode with all members still in the elastic stage; Model 3 strengthens the six weak zones of Model 2, and therefore, its stiffness is uniform. Model 3 is proposed to collapse in the strength failure mode when the members are still in the elastic stage By increasing the peak ground accelerations of seismic waves gradually, the shaking table tests were carried out until all three models collapsed （or locally collapsed）. On the basis of form vulnerability theory, topological hierarchy models of the test models were established through a clustering process, and various failure scenarios, including overall collapse scenarios and partial collapse scenarios, were identified by unzipping corresponding hierarchical models. By comparison of the failure scenarios based on theoretical analysis and experiments, it was found that vulnerability theory could effectively reflect the weak- ness zones in topological relations of the structures from the perspective of internal causes. The intemal mechanisms of the distinct failure characteristics of reticulated shells subjected to seismic excitations were also revealed in this process. The well-formedness of structural clusters, Q, is closely related to the collapse modes, i.e., uniform changes of Q indicate a uniform distribution of overall structural stiffness, which indicates that strength failure is likely to happen; conversely, non-uniform changes of Q indicate that weak zones exist in the structure, and dynamic instability is likely to occur.